Film track and aperture unit for projectors



1947. E. J. WIENKE 2,425,217

FILM TRACK AND APERTURE UNIT FOR PROJECTORS Filed Feb. 15, 1946 K I'll I fizz /erzf or" 2321a? J ZZ/ce7 /Ze Patented Aug. 5, 1947 FILE I TRACK AND APERTURE UNIT FOR 'PROJECTORS Emil. J. Wienke, Glen Ellyn, 111., assignor to Motiograph, Chicago, 111., alimited partnership of Illinois Application February 15, 1946, Serial 'No.- 647,939

2 Claims.

The present invention relates to a film track and aperture unit for motion picture projectors, and is particularly adapted for use with the construction shown in my co pending application, Serial No. 647,937, filed February 15, 1946, for Motion'picture projector. It is the principal purpose of this invention to provide -anovel film track and aperture unit whereby the aperture plate is removablymounted in such a way as to insure firmaccurate positioning, and the film is guided with respect to the aperture plate in such manner as to maintain alignment thereof by rotatable guides above and below the aperture in the plate, which guides force the film to follow a definite patch across the aperture.

It is a further purpose of the invention to provide a unit of this character which is self contained and easily taken apart for any repair or cleaning purpose.

The nature and advantages of my invention will appear more fully from the following description and the accompanying drawings. It should be understood, however, that the drawings and description are illustrative only, and should not be considered as limiting the invention except insofar as it is limited by the claims.

In the drawings:

Figure 1 is a face View of the film track and aperture unit showing it mounted to the supporting part of the projector,

Figure 2 is a fragmentary view partly in section illustrating the construction of the film guide rollers that guide the film across the aperture plate,

Figure 3 is a sectional view on the line 33 of Figure 1, and

Figures 4 and 5 together illustrate the aperture plate and the film tension shoe between which the film is guided.

Referring now to the drawings, my invention is embodied in a film track and aperture unit which comprises a body casting 5 that is adapted to be mounted upon an assembly base casting 6 that in turn is secured to a wall I of the projector. The base casting B is aligned with the wall I and secured thereto in proper position as outlined in my co-pending application mentioned above. The casting 5 has a flange portion 8 that is secured to the base casting B by a plurality of screws such as are shown at 9 and Ill.

The casting 5 is channeled on its front face as shown at I I to provide a seat for an aperture plate I2. The aperture plate is shown in perspective in Figure 4. It comprises twoguide ribs [3 and [4 with an intermediate panel portion 15, the

ribs projecting above the panel portionsothat the picture part of thefilm does not contact the plate. The ribs-tt and M-are'of' course polished smoothto oiferas: little wear as possible to the film itself. The-upper end it of the aperture plate is curled overand the lower ends'of the ribs Hand !4 are rounded as-indicated atlland E8. The light aperture 1-9 is of-course in'the portion 15 of the aperture plate i2. The ribs l3 and-L4 cooperate w'ith-corresponding ribs 28 and 2! of the film tension shoe 22, to form a guide for the side edges of the film. The details of mounting of the film tension shoe 22 are not described herein, since they form no part of the present invention.

In order to clamp the aperture plate 12 in position on the casting 5 I provide a rearwardly extending lug 23 midway of the aperture plate. This lug is riveted to the aperture plate and is provided with a tapered hole 2 extending transversely to the aperture plate with its axis parallel to the plane of the ribs l3 and 14-. The casting 5 is provided with a threaded aperture 25 to receive a threaded pin 2h. The axis of the pin 26 is ofiset rearwardly of the axis of the aperture 24, both axes of course being parallel to the guide face of the aperture plate E2. The pin 26 has a tapered end 21 extending into the aperture 26, so that by turning the pin 26 the lug 23 may be drawn back to tightly secure the aperture plate in the recess 11. The aperture plate is readily removable when the pin 26 is turned back far enough to remove the tapered portion 2'1 from the opening 24.

In order to guide the film accurately from top to bottom, of the track ribs l3 and I4, I provide upper and lower guide roller units 28 and 29. These units are each mounted by pins 30 and 3| that are anchored in upper and lower projecting portions 32 and 33 of the casting 5. The pins have conical tips and the guide roller units have conical recesses at their ends as illustrated in Figure 2 to receive the pins. Both of the guide roller units are the same in construction, and this detailed construction is illustrated in Figure 2. Each unit consists of a spindle 34 having a guide flange 35 at one end, and a projection 35 which has the conical recess to receive the pin 30. The spindle 34 has a reduced extension 31' which receives a sleeve 38 that carries a flange 39 forming a film guide opposite to the flange 35. The diameters of the sleeve 38 and the spindie 34 are the same, but the sleeve 38 is slidable on the reduced extension 3'! of the spindle. A spring 40 engages the outer face of the flange 39 so as to press it toward the flange 3-5. The spring is held by a threaded flanged sleeve 4| that threads onto the portion 42 of the extension 31. The portion 42 also has the conical recess for a pin 30. The sleeve 4| may of course be adjusted to give more or less tension on the spring 49 if that is desired.

The flanges 35 on the upper and lower spindles 34 are fixed in proper alignment with the guide rib 13 so as to form a fixed guide for the edge of the film both above and below the aperture Hi. The flanges 39 are spring pressed by the light springs 46 against the opposite edge of the film so as to maintain the film in engagement with the flange 35. This construction provides for accurate travel of the film past the film aperture under all conditions. Since the spindles are freely rotatable with the film as it travels past the aperture 19, the flanges 35 and 39 actually form guide rollers for insuring straight travel of the film across the aperture.

Having thus described my invention, I claim:

1. In a motion picture projector, a film track plate having guide portions at its side edges and having a light aperture between said portions, a support for said plate having a channel to receive said plate, a lug on the plate, said support having an opening receiving the lug, said lug having a tapered aperture therein the axis of which is transverse to the lug and generally par- 4 allel to the plane of the plate, and a lock pin threaded in the support on an axis offset rearwardly from the plate farther than the axis of the tapered aperture, said pin having a tapered end extending into the aperture.

2. In a motion picture projector, a film track plate having a light aperture therein, a support for said plate and a guide surface thereon to receive said plate, 2, lug on the plate, said support having an opening receiving the lug, said lug having a tapered aperture therein, the axis of which is transverse to the lug and generally parallel to the plane of the plate, and a lock pin mounted in the support on an axis offset rearwardly from the plate farther than the axis of the tapered aperture, said pin having a tapered end extending into the aperture.

EMIL J. WIENKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,828,768 Dina Oct. 27, 1931 1,880,406 Brown Oct. 4, 1932 1,987,623 Holman Jan. 15, 1935 2,120,249 Holman Jun 14, 1938 2,358,634 Boecking Feb. 6, 1945 

